Stuck-pump prevention device

Abstract

A stuck-pump prevention device includes: a pump; a recovery-liquid generator coupled to a fuel tank and generating a recovery liquid by cooling evaporative fuel generated in the fuel tank and condensing and recovering a low-boiling component included in the evaporative fuel; a first pipe allowing a discharge port of the recovery-liquid generator and a recovery-liquid inlet of the pump to communicate with each other; a first on-off valve that opens and closes the discharge port of the recovery-liquid generator; a second on-off valve that opens and closes the recovery-liquid inlet of the pump; and a control unit that opens and closes the on-off valves and controls driving of the pump. When a predetermined cleaning-control execution condition is satisfied, the control unit executes cleaning control involving opening the on-off valves and driving the pump to cause the recovery liquid to be taken into the pump through the first pipe.

1 . A stuck-pump prevention device comprising:
 a pump configured to generate negative pressure;   a recovery-liquid generator coupled to a fuel tank that stores fuel, the recovery-liquid generator being configured to generate a recovery liquid by cooling evaporative fuel generated in the fuel tank and condensing and recovering a low-boiling component of the fuel included in the evaporative fuel;   a first pipe configured to allow a discharge port of the recovery-liquid generator and a recovery-liquid inlet of the pump to communicate with each other;   a first on-off valve configured to open and close the discharge port of the recovery-liquid generator;   a second on-off valve configured to open and close the recovery-liquid inlet of the pump; and   a control unit configured to open and close each of the first on-off valve and the second on-off valve and control driving of the pump,   wherein the control unit is configured to, when a predetermined cleaning-control execution condition including an engine stoppage is satisfied, execute cleaning control comprising opening the first on-off valve and the second on-off valve and driving the pump to cause the recovery liquid to be taken into the pump through the first pipe.   
     
     
         2 . The stuck-pump prevention device according to  claim 1 , further comprising:
 a second pipe configured to allow a recovery-liquid outlet of the pump and the fuel tank to communicate with each other; and   a third on-off valve configured to open and close the second pipe,   wherein the control unit is configured to open the third on-off valve when executing the cleaning control.   
     
     
         3 . The stuck-pump prevention device according to  claim 2 , further comprising a fourth on-off valve configured to open and close an intake port of the pump,
 wherein the control unit is configured to close the fourth on-off valve when executing the cleaning control.   
     
     
         4 . The stuck-pump prevention device according to  claim 3 ,
 wherein the pump is a vane pump comprising vanes that have a substantially rectangular tabular shape and that are movable in a radial direction, and   wherein each of the vanes has a side surface provided with a groove extending radially outward.   
     
     
         5 . The stuck-pump prevention device according to  claim 4 , further comprising a filter disposed in the second pipe and configured to capture foreign matter included in the recovery liquid that is to be returned to the fuel tank. 
     
     
         6 . A stuck-pump prevention device comprising:
 a pump configured to generate negative pressure;   a recovery-liquid generator coupled to a fuel tank that stores fuel, the recovery-liquid generator being configured to generate a recovery liquid by cooling evaporative fuel generated in the fuel tank and condensing and recovering a low-boiling component of the fuel included in the evaporative fuel;   a first pipe configured to allow a discharge port of the recovery-liquid generator and a recovery-liquid inlet of the pump to communicate with each other;   a first on-off valve configured to open and close the discharge port of the recovery-liquid generator;   a second on-off valve configured to open and close the recovery-liquid inlet of the pump; and   circuitry configured to
 open and close each of the first on-off valve and the second on-off valve and control driving of the pump, and 
 execute cleaning control when a predetermined cleaning-control execution condition including an engine stoppage is satisfied, the cleaning control comprising opening the first on-off valve and the second on-off valve and driving the pump to cause the recovery liquid to be taken into the pump through the first pipe.